Oceanography and Atmospheric Sciences and Meteorology Commons^™

A 3-D Model Of The Auroral Ionosphere, Yishi Lee

Doctoral Dissertations and Master's Theses

A new 3-D model of the high latitude ionosphere is developed to study the coupling of the ionosphere with the magnetosphere and neutral atmosphere. The model consists of equations describing conservations of mass, momentum and energy for the six ionospheric constituents (O+, NO+, N+2 , O+2 , N+ and e-) and an electrostatic potential equation. This 3-D model is used to examine interrelated processes of ion heating, plasma structuring due to perpendicular transport, ion upflow, molecular ion generation, and neutral wave forcing. It is first validated by comparisons with a 2-D model, which uses similar mathematical and numerical approaches, and …

Optimizing Resolution And Uncertainty In Bathymetric Sonar Systems, Val E. Schmidt, Thomas C. Weber, Xavier Lurton

Center for Coastal and Ocean Mapping

Bathymetric sonar systems (whether multibeam or phase-differencing sidescan) contain an inherent trade-off between resolution and uncertainty. Systems are traditionally designed with a fixed spatial resolution, and the parameter settings are optimized to minimize the uncertainty in the soundings within that constraint. By fixing the spatial resolution of the system, current generation sonars operate sub-optimally when the SNR is high, producing soundings with lower resolution than is supportable by the data, and inefficiently when the SNR is low, producing high-uncertainty soundings of little value. Here we propose fixing the sounding measurement uncertainty instead, and optimizing the resolution of the system within …

Tips From The Board Of Broadcast Meteorology For Gaining The Certified Broadcast Meteorologist (Cbm) Designation, Rob Eicher

Publications

These notes are intended to maximize the likelihood that you will pass the AMS CBM evaluation on your first attempt. Typically half of first-time applicants pass the evaluation.

Climate Change Impacts On Precipitation Extremes Over The Columbia River Basin Based On Downscaled Cmip5 Climate Scenarios, Ghulam Hussain Dars

Dissertations and Theses

Hydro-climate extreme analysis helps understanding the process of spatio-temporal variation of extreme events due to climate change, and it is an important aspect in designing hydrological structures, forecasting floods and an effective decision making in the field of water resources design and management. The study evaluates extreme precipitation events over the Columbia River Basin (CRB), the fourth largest basin in the U.S., by simulating four CMIP5 global climate models (GCMs) for the historical period (1970-1999) and future period (2041-2070) under RCP85 GHG scenario.

We estimated the intensity of extreme and average precipitation for both winter (DJF) and summer (JJA) seasons …

Discontinuities And Alfvenic Fluctuations In The Solar Wind, G. Paschmann, S. Haaland, B. Sonnerup, T. Knetter

Dartmouth Scholarship

We examine the Alfvenicity of a set of 188 solar wind directional discontinuities (DDs) identified in the Cluster data from 2003 by Knetter (2005), with the objective of separating rotational discontinuities (RDs) from tangential ones (TDs). The DDs occurred over the full range of solar wind velocities and magnetic shear angles. By performing the Walen test in the de Hoffmann–Teller (HT) frame, we show that 77 of the 127 crossings for which a good HT frame was found had plasma flow speeds exceeding 80 % of the Alfven speed at an average angular deviation of 7.7◦; 33 cases had speeds …

Integrating Science & Policy, Abigail A. Carson

Honors Theses

Millions already owe their lives to scientists for their research and implementation of early warning devices such as a tornado warning. These warning systems are the beginning for what is to come if science continues to receive backing. Think of what could be accomplished in the next century if science and policy were to unite in the interest of protecting humans and the environment. It is imperative that environmental policies be based on sound science; to achieve this, political and scientific sectors must be integrated to produce effective and practical policies.

Interpretation Of Biological Activity Using An Acoustic Backscatter Sensor (Abs), Courtney Elliton

Honors Theses

Acoustics aid in the description of complex processes, such as the suspension of sand particles exposed to local hydrodynamic forces above a rippled bed (Cacchione, et al., 2008). Acoustic data can be applied to several aspects of the marine environment such as marine chemistry, biology, geology, and ecology. The acoustic data collected in this study was part of a larger, grant-funded project that focused on sediment transport and settlement preference on two offshore hardbottoms following beach renourishment along the heavily developed coast in northeastern South Carolina. Acoustic data collection was used in the larger project to describe changes in sediment …

Does Presence Of A Mid-Ocean Ridge Enhance Biomass And Biodiversity?, Imants G. Priede, Odd Aksel Bergstad, Peter I. Miller, M. Vecchione, Andrey Gebruk, Tone Falkenhaug, David S. M. Billett, Jessica Craig, Andrew C. Dale, Mark A. Shields, Gavin H. Tilstone, Tracey Sutton, Andrew J. Gooday, Mark E. Inall, Daniel O. B. Jones, Victor Martinez-Vicente, Gui Menezes, Tomasz Niedzielski, Thorsteinn Sigurdsson, Nina Rothe, Antonina Rogacheva, Claudia H. S. Alt, Timothy Brand, Richard Abell, Andrew S. Brierley, Nicola J. Cousins, Deborah Crockard, A. Rus Hoelzel, Age Hoines, Tom B. Letessier, Jane F. Read, Tracy Shimmield, Martin J. Cox, John K. Galbraith, John D. M. Gordon, Tammy Horton, Francis Neat, Pascal Lorance

Marine & Environmental Sciences Faculty Articles

In contrast to generally sparse biological communities in open-ocean settings, seamounts and ridges are perceived as areas of elevated productivity and biodiversity capable of supporting commercial fisheries. We investigated the origin of this apparent biological enhancement over a segment of the North Mid-Atlantic Ridge (MAR) using sonar, corers, trawls, traps, and a remotely operated vehicle to survey habitat, biomass, and biodiversity. Satellite remote sensing provided information on flow patterns, thermal fronts, and primary production, while sediment traps measured export flux during 2007–2010. The MAR, 3,704,404 km² in area, accounts for 44.7% lower bathyal habitat (800–3500 m depth) in the …

Sfa Weather Station-May 2013, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University

Weather Station Data

No abstract provided.

Climate Change Tipping Points: A Point Of No Return?, Elise Lequire

Joint Fire Science Program Digests

Summer 2012 saw records fall for intensity of drought and number, size, and cost of wildfires in the Central and Western United States, and the climate forecast calls for more of the same in the near and distant future. When wildfire breaks out, emergency responders decide their immediate strategy based on past experience and quick judgment calls. But in the long term, land managers need to plan for a warmer climate on a time scale of decades, or even a century or more, to better reflect the life span of trees and forests. Studies supported by the Joint Fire Science …

Ecological Design In The Ozarks - Workshop And Lake Frances Charrette, Steven D. Patterson, Brian E. Haggard, Mark E. Boyer

Arkansas Water Resources Center Technical Reports

No abstract provided.

Middle Atmosphere Temperature Results From A New, High-Powered, Large-Aperture Rayleigh Lidar, Leda Sox, Vincent B. Wickwar, Joshua P. Herron

Conference publications

In June–July 2012, observations were carried out using the recently upgraded, large-aperture, Rayleigh-scatter lidar system located at the Atmospheric Lidar Observatory (ALO) on the campus of Utah State University, in Logan, UT (41.7 N, 111.8 W). This time period was significant because it enabled us to observe the annual temperature minimum in the upper mesosphere-lower thermosphere region. The data collected during the campaign were analyzed for temperatures between ~70–109 km. The results above ~95 km are the first obtained with a Rayleigh-scatter lidar, extending the technique well into the lower thermosphere. A great deal of variability from night-to-night is evident …

Comparative Visual Function In Predatory Fishes From The Indian River Lagoon, D. Michelle Mccomb, Stephen M. Kajiura, Andrij Horodysky, Tamara M. Frank

Marine & Environmental Sciences Faculty Articles

Visual temporal resolution and spectral sensitivity of three coastal teleost species (common snook [Centropomus undecimalis], gray snapper [Lutjanus griseus], and pinfish [Lagodon rhomboides]) were investigated by electroretinogram. Temporal resolution was quantified under photopic and scotopic conditions using response waveform dynamics and maximum critical flicker fusion frequency (CFF_max). Photopic CFF_max was significantly higher than scotopic CFF_max in all species. The snapper had the shortest photoreceptor response latency time (26.7 ms) and the highest CFF_max (47 Hz), suggesting that its eyes are adapted for a brighter photic environment. In contrast, the …

On The Export Of Reactive Nitrogen From Asia: NoX Partitioning And Effects On Ozone, T H. Bertram, Paul J. Wooldridge, Jack E. Dibb, Robert C. Cohen, A E. Perring

Earth Sciences

The partitioning of reactive nitrogen (NO_y was measured over the remote North Pacific during spring 2006. Aircraft observations of NO, NO₂, total peroxy nitrates (ΣPNs), total alkyl and multi-functional nitrates (ΣANs) and nitric acid (HNO₃, made between 25° and 55° N, confirm a controlling role for peroxyacyl nitrates in NO_x production in aged Asian outflow. ΣPNs account for more than 60% of NO_y above 5 km, while thermal dissociation limits their contribution to less than 10% in the lower troposphere. Using simultaneous observations of NO_x, ΣPNs, ΣANs, HNO₃ and average …

Scottish Nephrops Survey Phase Iii: Evaluation Of Measures For Reducing Bycatch And Discards In A Nephrops Fishery, Rosanna Milligan, Amaya Albalat, Douglas Neil

Marine & Environmental Sciences Faculty Reports

No abstract provided.

Acting To Address The Ocean-Related Impacts Of Climate Change On Human And National Security, With Recommendations For Priority Actions Drawn From The Discussions Of The Global Conference On Oceans, Climate And Security At The University Of Massachusetts Boston, Robbin Peach, Felix Dodds, Michael Strauss, Collaborative Institute For Oceans, Climate And Security, University Of Massachusetts Boston

Collaborative Institute for Oceans, Climate and Security Publications

In the course of the past calendar year the United States has been struck by a series of droughts, tornadoes, hurricanes, blizzards, wildfires, and floods whose size and path of resulting damage defy previously established patterns. The U.S. thus joins nations on every continent that have increasingly experienced extreme and extremely damaging weather events over the past two decades.

At the same time, the world’s oceans have been exhibiting a less-visible but equally dangerous sequence of temperature rise, acidification increase, fish kills, coastal erosion, salinity shifts, algae blooms, and steady decreases in commercially available fish and shellfish species.

Those impacts …

De Novo Transcriptome Analysis Of The Marine Sponge Cinachyrella Spp: A Potential Model Organism For Oil And Dispersant Ecotoxicology, Emily Smith

HCNSO Student Theses and Dissertations

In order to study the potential effects of an oil spill on coral reef organisms, the marine sponge, Cinachyrella spp. was investigated. In this study, Cinachyrella spp. was placed in a closed aquaculture system and exposed to sub-lethal water-accommodated fractions (WAFs) of Macondo crude oil and chemically-enhanced water accommodated fractions (CE-WAFs) of the dispersant, Corexit 9500, over a 24-hour time course, in order to model the BP Deepwater Horizon oil spill and oil spill sponge response. Illumina RNA sequencing and gene expression analysis utilizing hierarchical clustering, principal component analysis, and KEGG bioinformatic database generated 34,147 unique transcripts with …

Marine Phytoplankton Temperature Versus Growth Responses From Polar To Tropical Waters- Outcome Of A Scientific Community-Wide Study, Philip W. Boyd, Tatiana A. Rynearson, Evelyn A. Armstrong, Feixue Fu, Kendra Hayashi, Zhangxi Hu, David A. Hutchins, Elena Litchman, Margaret R. Mulholland, Uta Passow, Robert F. Stzepek, Kerry A. Whittaker, Elizabeth Yu, Mridul K. Thomas

OES Faculty Publications

“It takes a village to finish (marine) science these days”

Paraphrased from Curtis Huttenhower (the Human Microbiome project)

The rapidity and complexity of climate change and its potential effects on ocean biota are challenging how ocean scientists conduct research. One way in which we can begin to better tackle these challenges is to conduct community-wide scientific studies. This study provides physiological datasets fundamental to understanding functional responses of phytoplankton growth rates to temperature. While physiological experiments are not new, our experiments were conducted in many laboratories using agreed upon protocols and 25 strains of eukaryotic and prokaryotic phytoplankton …

Springtime Contribution Of Dinitrogen Fixation To Primary Production Across The Mediterranean Sea, E. Rahav, B. Herut, A. Levi, Margaret Mulholland, I. Berman-Frank

OES Faculty Publications

Dinitrogen (N-2) fixation rates were measured during early spring across the different provinces of Mediterranean Sea surface waters. N-2 fixation rates, measured using N-15(2) enriched seawater, were lowest in the eastern basin and increased westward with a maximum at the Strait of Gibraltar (0.10 to 2.35 nmol NL-1 d(-1), respectively). These rates were 3-7 fold higher than N-2 fixation rates measured previously in the Mediterranean Sea during summertime and we estimated that methodological differences alone did not account for the seasonal changes we observed. Higher contribution of N-2 fixation to primary production (4-8 %) was measured in the western basin …

Agricultural Production And Stability Of Settlement Systems In Upper Mesopotamia During The Early Bronze Age (Third Millennium Bce), Tuna Kalayci

Graduate Theses and Dissertations

This study investigates the relationship between rainfall variation and rain-fed agricultural production in Upper Mesopotamia with a specific focus on Early Bronze Age urban settlements. In return, the variation in production is used to explore stability of urban settlement systems. The organization of the flow of agricultural goods is the key to sustaining the total settlement system.

The vulnerability of a settlement system increases due to the increased demand for more output from agricultural lands. This demand is the key for the success of urbanization project. However, without estimating how many foodstuffs were available at the end of a production …

Investigation Of Human-Induced Land Use Changes Under Present And Future Climate Projections In Southern Idaho, Korri Allen Anderson

Boise State University Theses and Dissertations

Water is the lifeblood of Idaho agricultural practices. Under future climate, water shortages may occur and better water management will need to occur under these conditions. The role of irrigation under a changing climate has not been previously investigated in the Snake River Basin. Irrigation schemes implemented in the NOAH Land Surface Model are tested within the Weather Research and Forecast Model 3.4 at 4-km resolution. The goals of this research are to investigate the effect of irrigation-induced cooling on local and regional climate in Southern Idaho, under present and future climate projections, and to diagnose irrigation-induced changes to surface …

A Cradle To Farm Gate Life Cycle Analysis Of Water Use In U.S. Pork Production, Eric Boles

Graduate Theses and Dissertations

The intent of this study was to analyze water use across a range of regions, scales and practices of the U.S. pork industry. A Life Cycle Assessment of water use within the pork supply chain was performed. Cumulative water use was the environmental impact category used in the LCA to evaluate the impacts of pork production processes throughout the pork supply chain. The functional unit for the analysis was the volume of water required to produce one kilogram of swine (live weight) at the farm gate.

A comprehensive literature review was used to design and propagate algorithms for the National …

An Examination Of The Mechanisms And Environments Supportive Of Bow Echo Mesovortex Genesis, George Limpert

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Low-level mesovortices are associated with enhanced surface wind gusts and high-end wind damage in quasi-linear thunderstorms. Although damage associated with mesovortices can approach that of moderately strong tornadoes, skill in forecasting mesovortices is low. The overarching goal of this work is to understand mesovortices and how they develop, to improve the skill in forecasting them. This was done by developing a climatology of mesovortices, which required a tracking algorithm, and numerical simulations were conducted to answer questions that could not be answered through the observational data. A climatology of mesovortices was constructed from 44 events during 2009 and 2010 to …

Integrating, Developing, And Testing Methods To Generate More Cohesive Approaches To Biogeographic Inference, Mallory Elizabeth Eckstut

UNLV Theses, Dissertations, Professional Papers, and Capstones

As a fundamental component of the developing discipline of conservation biogeography, broadscale analyses of biotic assembly and disassembly across multiple temporal and spatial scales provide an enhanced understanding of how geologic transformations and climate oscillations have shaped extant patterns of biodiversity. As with any scientific field, there are limitations in the case of biogeographic historical reconstructions. Historical reconstructions are only as robust as the theoretical underpinnings of the methods of reconstruction (including data collection, quality, analysis, and interpretation). Nevertheless, historical reconstructions of species distributions can help inform our understanding of how species respond to environmental change.

My dissertation takes a …

Soil Moisture Recognition And The Spatial Distribution Of Storm Activity In The Mojave Desert Using High-Resolution Aster And Modis Imagery For Thermophysical Mapping, Russell J. Skuse

UNLV Theses, Dissertations, Professional Papers, and Capstones

Climate models suggest that the Mojave Desert ecoregion is vulnerable to becoming drier in the future, and as the human population grows and development increases, environmental stresses will likely increase. Determining the spatial distribution and variation of soil moisture on a regional scale is an essential component to climate change, hydrologic, and habitat analyses. Soil permeability and sediment stability are characteristics that have been shown to be measurable from remote sensing observations. The primary objective of this project is to map the mechanical composition of the surface materials in the Mojave Desert ecoregion with implications for soil permeability, sediment stability, …

The Evaluation Of Water Storage In Death Valley Using Grace Satellite Data, Maile Sweigart

UNLV Theses, Dissertations, Professional Papers, and Capstones

As drought conditions spread across the United States, concerns over water supplies, water use, and water management policies are growing and possible contributing environmental factors are continually being scrutinized. This thesis examines Death Valley as an analog for Southern Nevada and utilizes NASA EOS data, combined with ancillary climate data, to assess the effect of decadal climate variability on groundwater storage in the Death Valley area. Historical climate data, combined with satellite imagery observations, were compiled and calculated for analyses. Conclusions derived from statistical analyses infer trends between GRACE (Gravity Recovery and Climate Experiment) satellite data and fluctuating levels of …

The Consciousness Of Water: Narrative Flows, Environmental Change, And The Voice Of Yemen, Tricia Nellessen

Graduate Theses and Dissertations

Icebergs are melting in the Arctic. The Gulf of Mexico is warming and producing hurricanes such as Katrina. The delta of the southern United States is drying. And, Yemen will be the first country in modern history to experience a lack of accessible ground water, as soon as 2017 possibly. Yemen's situation has been tracked by scholars and governments since the 1960s. Despite this fact, cities have expanded in Yemen and the population has increased its use of water while little has been invested in desalination or infrastructure to offset growth. Climate change has affected humans for thousands of years; …

Understanding Effects Of Changes In Land Use, Environmental Parameters, Habitat Characteristics On The Great Basin Aquatic Invertebrates Using Ecological Stoichiometric Theory, Knut Mehler

UNLV Theses, Dissertations, Professional Papers, and Capstones

Many freshwater ecosystems in the Great Basin have undergone dramatic alteration over the past decades due to groundwater withdrawal, water diversion and changes in land use. These changes have affected benthic food web dynamics by altering the availability of chemical key elements for primary and secondary producers, by loss of biodiversity and extinction of endemic species. However, only few studies are available that addresses the link between changes in land use, habitat characteristics and its effects on benthic macroinvertebrates (BMI) communities comprehensively and little attention has been given to integrating physiochemical aspects to link ecosystem functions.

This dissertation analyzes the …

Lunar Tidal Effects In The Electrodynamics Of The Low-Latitude Ionosphere, Brian David Tracy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In order to model and perform better forecasts of the upper atmosphere, we have studied variations in the equatorial ionosphere due to lunar tidal forcing. We used extensive measurements made by the Jicamarca Unattended Long-Term Investigations of the Ionosphere and Atmosphere (JULIA) and Incoherent Scatter Radar (ISR) systems at Jicamarca, Peru during geomagnetic quiet conditions to determine the season, local time, and lunar age-dependent lunar tidal effects on equatorial vertical plasma drifts. The amplitudes and phases of the semimonthly and monthly lunar tidal perturbations were derived using a least squares method. Our results indicate that, as expected, lunar tidal effects …

Colorado River Cutthroat Trout Habitat Resistance And Resilience To Climate Change, Kate H. Olsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Government agencies and private organizations spend large amounts of public money attempting to return ecosystems to a more natural state, which have often been harmed or even destroyed as a result of modern development. Colorado River cutthroat trout, Oncorhyncus clarki pleuriticus, are a subspecies of cutthroat trout. Cutthroat trout live in the Rocky Mountains of the western United States. The population of this particular subspecies has been severely reduced by human actions, and currently only 12% of its historic populations still exist. To improve the condition of cutthroat trout, fisheries professionals and biologists are working to restore natural populations. …